This application is based upon and claims the benefit of Japanese Patent Applications No. 2000-255591 filed on Aug. 25, 2000 and No. 2001-141965 filed on May 11, 2001, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an inside/outside air switching device using a rotary door. More particularly, the preset invention relates to a structure for partially introducing inside air in an outside air introduction mode.
2. Description of Related Art
In an inside/outside air switching device disclosed in JP-A-11-348529, an inside/outside air switching box has a first inside air introduction port and a second inside air introduction port for introducing inside air inside a passenger compartment, and an outside air introduction port for introducing outside air outside the passenger compartment. In the inside/outside air switching box, the outside air introduction port is provided to be proximate to the first inside air introduction port with respect to the second inside air introduction port. The second inside air introduction port is an auxiliary port for increasing an inside air amount. An inside/outside air switching door and an inside air auxiliary door are rotary type doors, and are disposed in the inside/outside air switching box. The inside/outside air switching door is used for opening and closing the first inside air introduction port and the outside air introduction port. The inside air auxiliary door is used for opening and closing the second inside air introduction port.
That is, in an inside air introduction mode, inside air is introduced from both the first and the second inside air introduction ports, so that a large amount of air is introduced and an air conditioning capacity is improved. However, in an outside air introduction mode, both the first and second inside air introduction ports are closed, and only outside air with a large air-conditioning load is introduced from the outside air introduction port. Therefore, an air conditioning device having a large air-conditioning capacity is required. Accordingly, it is necessary to increase a volume of the air conditioning device or motive power of a blower fan.
In addition, the inside air auxiliary door and the inside/outside air switching door are operatively linked through a link member to be simultaneously rotated. Therefore, a structure of the link member for rotating both the doors together is complicated and a large number of components are required.
In view of the foregoing problems, it is an object of the present invention to provide an inside/outside air switching device having first and second inside air introduction ports, in which an inside air auxiliary door for opening and closing the second inside air introduction port is operated using a negative pressure generated by operation of a blower fan, so that inside air can be partially introduced in an outside air introduction mode while motive power for rotating the inside air auxiliary door can be saved.
According to the present invention, in an inside/outside air switching device, an inside/outside air switching box has first and second inside air introduction ports and an outside air introduction port, an inside/outside air switching door is disposed for selectively opening and closing the first inside air introduction port and the outside air introduction port, an inside air auxiliary door is disposed in the inside/outside air switching box for opening and closing the second inside air introduction port, and a blower unit is disposed at a downstream air side of the inside/outside air switching door for sucking and blowing air introduced from the outside air introduction port and the first and the second inside air introduction ports. The inside air auxiliary door has an upper edge supported in the inside/outside air switching box, and is rotatable around the upper edge to open the second inside air introduction port due to a pressure difference between an inner side of the inside/outside air switching box around the inside air auxiliary door and an inner side of a passenger compartment when the blower unit operates. Accordingly, in an outside air introduction mode where the inside/outside air switching door opens the outside air introduction port and closes the inside air introduction port, outside air can be introduced from the outside air introduction port, while inside air is introduced from the second inside air introduction port opened by the inside air auxiliary door that is driven using the pressure difference.
Because the inside air auxiliary door is operated by using the pressure difference, motive power for rotating the inside air auxiliary door is saved. In addition, because inside air can be partially introduced while outside air is introduced from the outside air introduction port in the outside air introduction mode, an air-conditioning capacity is improved in a vehicle air conditioner while consumed power for adjusting air state blown into the passenger compartment is reduced. On the other hand, in an inside air introduction mode, since inside air is introduced from both the first inside air introduction port and the second inside air introduction port, a large amount of inside air is introduced. Moreover, because the inside air auxiliary door is operated only using the pressure difference, a link member for driving the inside air auxiliary door is unnecessary, and production cost of the inside/outside air switching device can be reduced.